London: Excessive work on a computer, including staring at the screen for a long time, creates a craving for sweet treats like chocolate and biscuits.
The mental stress of computer work triggers changes in blood sugar and hormone levels that trick the brain into thinking it has worked off lots of calories that need to be replaced. Watching television has the same effect, experts at the International Congress on Obesity in Stockholm have said.
Office workers who want to keep trim should take regular screen breaks, and even consider typing while standing up, Jean-Philippe Chaput, a researcher from the University of Copenhagen, has suggested.
Chaput started the research after noticing how one regularly snacked on chocolate biscuits when doing computer work.
He asked one group of female students to condense some text into an on-screen summary and another group to simply relax for 45 minutes.
Those doing the computer-based task burnt just three more calories than the others, but ate much more food when given access to a buffet afterwards. In fact, they took in an extra 230 calories - the equivalent of a two-fingered Kit Kat.
"Working on your computer is sedentary and doing nothing increases your weight. But use of them also increases your appetite as well so there is a double whammy in effect," Chaput was quoted as saying by Daily Mail.
Chaput will now look at whether computer games, in which users mime a sport, also lead people to eat more.